Various devices have been proposed for modifying boats to enhance the wake of the boat. An enhanced wake increases the thrill and challenge of water skiing or water boarding behind a boat. The greater the wake, the more opportunity for stunts, thrills and competition. The wake of a power boat can be increased by the addition of weight in the stern. One way of lowering the stern of a boat in the water to increase the wake has been the use of weights such as concrete blocks. However, the use of weights in cumbersome and difficult to install and remove, and if a mishap occurs in the handling of weights, the boat may be severely damaged.
U.S. Pat. No. 5,787,835 to Remnant describes a lightweight, portable container located generally above the water line in the stern of a boat in order to add weight to the stern and enhance the wake of the boat. The container is formed from an outer bag and an inner, liquid impermeable bladder positioned within the bag and an inner, liquid impermeable bladder positioned within the bag and protected form puncture and abrasion by the bag. The container is carried on a flat surface near the stern of the boat and is held in place by straps. The bladder is filled with water, normally by a garden hose or an electric pump, through one or more nozzles accessed through openings in the bag. A hose is also used to drain the bag either over the side or through the bilge of the boat after the bag has been suitably repositioned or rotated.
Larson et al U.S. Pat. No. 5,979,350 discloses a boat having two ballast tanks positioned at the sides of the stern of the boat and extending toward the center of the stern, the ballast tanks projecting substantially above the water line.
Hunt U.S. Pat. No. 3,085,535 describes a watercraft having a tunnel which runs essentially the length of the hull and fills with water through the transom at its open rear end when the hull is at rest or moving at low speed. A vent is provided at the closed forward end of the tunnel. The ballast afforded by the water is said to provide increased stability, particularly in reducing the tendency of certain V-shaped hulls to yaw in following seas. As the watercraft accelerates, the water flows out of the rear of the tunnel.
Moesly U.S. Pat. No. 3,503,358 discloses another V-shaped hull watercraft, with outboard motor, having two compartments for containing ballast water, forward compartment A, and centrally located compartment B (which can extend rearwardly to the transom). Compartments A & B are each vented. A valve assembly is opened to fill compartments A & B via a scoop which is lowered when the boat is moving forward. Moesly relies on the scoop to fill the compartments A & B. This can occur only when the water craft is in motion.
Jessen et al U.S. Pat. No. 6,234,099 B1 discloses a water craft including an engine of sufficient thrust to create an enlarged wake at the stern of the boat as the boat moves along the surface of a body of water, and two water tight compartments positioned below the waterline having a sealable opening at the stern of the boat below the water line. The water tight compartments extend from the stern to a point forward of the engine. The compartment is adapted to contain liquid water in an amount sufficient to enhance or equalize the size of the boat wake. The opening is adapted to be opened to drain out the water.